In the practice of heat exchange wherein the heat exchange fluid comprises both a vapor phase and a liquid phase, it is important for the attainment of efficient heat exchange that the vapor and liquid phases of the heat exchange fluid flow through the heat exchanger with a substantially homogeneous flow. The issue of homogeneous flow and the problems resulting from substantial deviation from homogeneous flow are particularly important when the heat exchange fluid is a multicomponent heat exchange fluid, such as a multicomponent refrigerant fluid, which comprises two or more components having different boiling points. In such cases the two phase mixture is separated into a vapor phase and a liquid phase which are introduced separately and mixed in the heat exchanger.
One phenomenon which results in deviations from homogeneous flow in a heat exchanger is flow reversal. If the vapor mass fraction of the heat exchange fluid is very low, the vapor velocity may be low and liquid may drain into the vapor inlet header and become trapped thereby removing this material from circulation in the heat exchange circuit. This problem of flow reversal may be addressed by increasing the local vapor velocity, but this solution increases the cost and reduces the efficiency of the heat exchange.
Another phenomenon which results in deviations from homogeneous flow in a heat exchanger is liquid logging. If the vapor mass fraction is very low, the liquid and vapor phases have a tendency to separate so as to provide the vapor with a path of least resistance through the heat exchanger. This results in the liquid phase becoming trapped within the heat exchanger and markedly reduces the efficiency of the heat exchange.
Accordingly it is an object of this invention to provide a heat exchanger distributor for a multicomponent heat exchange fluid which prevents flow reversal and liquid logging thereby ensuring substantially homogeneous flow of vapor and liquid phases of the heat exchange fluid even when the local fluid velocity and the vapor mass fraction of the heat exchange fluid are relatively small.